


The Lack Of

by SardonicMemory



Category: Undertale (Video Game)
Genre: AU, Alternate Universe, Alternate Universe - Canon Divergence, Angst, Anxiety, Bittersweet, Character Death, Character Turning Insane, Depression, Established Relationship, Flashbacks, Fluff, Gaster doesn't die, Gaster lives, Gen, Good W. D. Gaster, Hallucinations, Headcanon, M/M, Major character death - Freeform, Not Beta Read, Not Canon Compliant, POV First Person, POV Third Person, POV W. D. Gaster, Panic Attacks, Pre-Accident W. D. Gaster, Science!Sans - Freeform, Scientist Sans (Undertale), Scientist W. D. Gaster, Suicide, The Author Regrets Nothing, The Core (Undertale), W. D. Gaster is not related to Skelebros, but the rest is in third person, headcanons, insane character, losing loved ones, prologue is in first person, puns
Language: English
Status: In-Progress
Published: 2018-12-13
Updated: 2019-08-03
Packaged: 2019-09-17 12:47:10
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 4
Words: 1,032
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16974840
Author URL: https://archiveofourown.org/users/SardonicMemory/pseuds/SardonicMemory
Summary: An AU in which Sans disappeared instead of Gaster.How will this development affect the game and the people who inhabit it?Notes: World building and becoming even more attached to the characters before all the angst happens so it's pretty slow. Cross posted on wattpad under the same username and title. Please be mindful of the tags.





	1. Prologue

**Notes for the Chapter:**

> This was posted on December 20, 2018 at 10:12 pm. I live in the Philippines, by the way.  
> I hope you enjoy :)
> 
> Edited on August 3, 2019 at 11:41 pm

All that could be heard was heavy breathing. It poisoned the air and everything around it.

 

A small figure was standing near the rails. Shaky hands gripped the metal, a rattling noise coming from bone hitting steel.  

 

Footsteps.

Someone was walking, no- someone was running. They were coming to get him. They were trying to stop him.

 

_**don't don't don't don't don't** _

 Jumbled thoughts coming to a close, screaming a single word, begging the monster to stop running.

One leg swung over the rails.

'one down, one to go,' the figure thought.

 

The bright light was calling out to him, pulling him into the  _ ~~ **ⱱǾɨƉ**~~_ ~~~~.

 

"Sans!"

Yelling, why were they yelling? How did they notice? He was so  _sure_ they wouldn't notice him gone.

 

Frantic eyelights were moving left and right, left and right.

'quick. i have to be quick.'

 

The breathing got louder. The rattling got stronger. 

He wanted it all to  _end_. He leaned to the right, a small movement that cost everything.

 

The footsteps got louder, louder, **ḹȪȔḏɇꝚ**. A rush of air ran through his bones. He felt  _alive_. He felt  _real_.

 

The footsteps stopped at the door.

 

 

But he was gone.

 

White light burst through the room. The only thing that could be heard was Dr. Gaster's screams, calling out for  _ ~~ **ᵴⱥȠᶊ**~~_.

 

It was over.

**Notes for the Chapter:**

> Word Count: 219 words


	2. Irritable

**Summary for the Chapter:**

> oof is this a vent chapter i see?

**Notes for the Chapter:**

> Posted on January 5, 2019. 11:28 pm, Philippines.
> 
> Edited on August 3, 2019 at 11:58 pm

_Click, click, click_.

 

A skeletal hand was clicking a blue pen over and over.

 

 _Thud_.

 

A groan of despair filled the air. Gaster had slammed his head on the desk, frustrated. Constantly staring at the plans of the core was starting to hurt his eyelights.

 

Gaster made a glance at the clock and sighed. "I need a break."

 

Gaster took the mug of coffee left on his desk and walked out of his office.

Deciding to take the stairs, he started on his journey to the break room. 'Walking should help this unbearable headache,' he thought. On the way there, he passed by Alphys.

 

She seemed to be in a hurry, her clawed hands shaking. She was carrying a mountain of paperwork, struggling not to drop them.

 

Gaster decided to leave her be, not wanting to startle her.

 

He made a sharp turn to the left and went down another set of stairs. 'Almost there,' he thought.

 

He walked to the double doors, his steps making annoyingly loud tapping sounds on the sterile tiles.

 

The doors swung open with a loud creak. Gaster sighed once again, his right eye twitching in annoyance.

The fluorescent lights were starting to make him even more irritable, the glaring brightness felt like they were stabbing his eyelights.

 

Other scientists could be seen sitting at the tables. Some of them were eating or drinking coffee, others were just chatting idly.

 

Gaster stalked over to an empty table and practically fell onto the seat. He gave out a loud huff and glared at the inoffensive table. Poor table, it committed no crime yet it was still treated so horribly.

 

Drinking coffee, he tiredly glanced around the room. Normally, the bright colored monsters would bring him joy. It was a good change from the constant whiteness of the lab, after all. Now, however, the stark difference only served to aggravated him more.

 

 Annoyed, he stood up and walked out of the room. His sudden entry and exit hasn't been unnoticed by the other monsters in the room. 

 

They cast him worried looks, all of which unnoticed by the receiver.

 

 

He dragged his feet back up the steps and entered his office. The door was closed as softly as possible.

 

He made a slow trek to his desk and sat back down. He pinched his nasal bone in tired frustration.

 

* * *

 

 

The day was over and Gaster was fixing his things. It lasted too long, in his opinion. He rubbed at his eyes, the pain still nagging at him at the back of his mind.

 

When he walked out of the office, he bumped into Sans. "yo, doc. what happened to you?" Sans all but graciously asked.

Gaster let out a tired groan and replied. "It was a bad day. Everything was too much."

Honestly, if Gaster could just get a hold of himself, he would be a lot more productive. Fortunately and unfortunately, Sans disagreed with that sentiment.  

 

"aw, g. you wanna stay at my house for a bit?" A tempting offer, but Gaster declined. "alright, if you're sure."

 

They walked quietly down the hallway. Sans didn't want to make the situation worse for Gaster by talking.

 

After a quiet wave of goodbye, they went off to their own homes.

 

**Notes for the Chapter:**

> Word Count: 542 words


	3. Chapter 3

I'm sorry guys.


	4. Hot Air Goes Up, Cold Air Goes Down

**Notes for the Chapter:**

> Updated on August 3, 2019 at 12:10 pm

The orange heat was suffocating. It seemed to double down on everyone, distracting them.

 

Some of the scientists were sent home, due to their more prone structure. The scientists that were left in the lab had just as much progress as the ones at their houses. The heat wave and the lack of their co-workers hindered the amount of work they would usually accomplish.

 

Thankfully, two skeletons were sent to investigate and find the source of the problem. Gaster and Sans were walking side by side, both having their own bags slung over their shoulders.

 

With a destination in mind, they made conversation. "so, g, how's the core moving along?" Sans asked. "The current model needs some work. Hopefully it isn't the cause for the rise in temperature." Gaster sighed. "Best case scenario, we'll have to remodel the core. What are you working on?"

 

"tibia honest, it's just a small side project. i'm working on displacing matter. see if teleporting is possible, heh." Gaster made a small noise at that and looked at the smaller skeleton. He opened his mouth, about to ask him for more details, when Sans made a sudden stop. "we're here."

 

The air, although hot, felt cold and unforgiving. In front of them stood the entrance to the core. "i have a bad feeling about this," Sans commented.

 

The core was at the bottom of the pit. Powered by magic and the earth, it was made to bring electricity to the underground.

 

They looked at each other, apprehension on one face and a grim expression on the other, then they quickly went to work. 

**Notes for the Chapter:**

> Word Count: 269 words


End file.
